1. Field of the Invention
The invention relates to the field of electronic devices, and in particular, to a method and structure for accurately and neatly assembling a memory card-type electronic apparatus.
2. Related Art
Memory cards are widely used, for example, for storing digital pictures captured by digital cameras. One useful format is the Secure-Digital (SD) format, which is an extension of the earlier MultiMediaCard (MMC) format. These and other similar card-like structures are collectively referred to herein as “memory cards”. Such memory cards are also useful as add-on memory cards for other devices, such as portable music players, digital still cameras (DSCs), personal digital assistants (PDAs), and even notebook computers. SD cards are hot-swappable, allowing the user to easily insert and remove SD cards without rebooting or cycling power. Since the SD cards are small, durable, and removable, data files can easily be transported among electronic devices by being copied to an SD card. SD cards are not limited to flash-memory cards, but other applications such as communications transceivers can be implemented as SD cards.
An important aspect of most memory card structures is that they meet size specifications for a given memory card type. In particular, the size of the casing or housing, and more particularly the width and thickness (height) of the casing/housing, must be precisely formed so that the memory card can be received within a corresponding slot (or other docking structure) formed on an associated card-hosting device. For example, using the SD card specifications mentioned above, each SD card must meet the specified 24 mm width and 2.1 mm thickness specifications in order to be usable in devices that support this SD card type. That is, if the width/thickness specifications of a memory card are too small or too large, then the card can either fail to make the necessary contact pad-to-card-hosting device connections, or fail to fit within the corresponding slot of the associated card-hosting device.
One conventional method for manufacturing memory cards that meet required size specifications includes using housing formed by two prefabricated covers that mounted over the PCBA. One shortcoming of this approach is that the covers are fabricated separately and then attached to the substrate using a relatively adhesive process that is tedious and subject to failure. That is, the fabrication of memory cards using glued-together covers increases production and assembly costs due to the small size of the areas subjected to the gluing (adhesive) process and extra fixtures or equipment needed to complete the process. In addition, there is always a void space formed underneath the plastic housing after the gluing process, creating a barrier for customer acceptance. Further, the adhesive is subject to failure, thereby causing the covers to become detached and exposing the PCBA to contamination or undesirable tampering.
What is needed is a card-type electronic apparatus housing and assembly method that enables high production throughput by way of cost-efficient molding techniques that avoid the problems associated with conventional production methods.